1. Field of the Invention
The present invention relates to a system of electronic reprographics and, more particularly, to a system of electronic reprographics in which copy sensitive jobs are handled in a specific manner.
2. Description of the Related Art
In light lens printing systems, a lamp or flashing unit flashes light on a document and has an image created synchronously on a photoreceptor belt. The photoreceptor belt picks up toner from which a copy is made.
In electronic reprographic printing systems, a document or series of documents comprising at least one print job are successively scanned. The documents can be scanned either by a scanner in the system or by a scanner located elsewhere. When the scanner is located elsewhere, the image signals are transferred via an electronic network input to the system for processing. Image signals obtained are electronically stored. The signals are then read out successively and transferred to a printer for formation of the images on paper. Once a document is scanned, it can be printed any number of times or processed in any number of ways (e.g., words deleted or added, image magnified or reduced, etc.). If a plurality of documents comprise a job which is scanned, the processing or manipulation of the scanned documents can include deletion of one or more documents, reordering of the documents into a desired order, or addition of a previously or subsequently scanned document or documents. The printing or processing can be relatively synchronous with scanning, or asynchronous after scanning. If asynchronous, a time interval exists between scanning and printing or processing. The system can then accumulate a number of scanned jobs in the system memory for subsequent processing or printing. The order of the jobs to be printed may be different from the order of jobs as scanned depending on the priority of the jobs and the desires of the operator for increasing productivity or through-put and decreasing printer or scanner down-time.
For a variety of reasons, operation in an electronic reprographic system can be interrupted. This can be the result of a scanner or printer fault, hardware or software faults, paper misfeed, jam, intentional interruption, memory loss, etc. Upon such an interruption due to scanner fault, the operator, not knowing precisely where the scanner ceased operation, must either scan the entire job over again, initiate scanning at a document believed to precede the last scanned document and remove duplicate sheets from the job, or proof what has been scanned so far. When a crash occurs while the scanner is building a job, documents present in the paper path can be damaged and the integrity of the job cannot be guaranteed.
Copy sensitive jobs, or jobs composed of non-interchangeable, non-uniform sets, each set being unique in some way, can be handled by electronic reprographic systems having an electronic network input. This is possible because the electronic reprographic system has the capability to handle groups of sheets as a distinct set. A plurality of sets can then be processed as a job by the system.
System malfunctions such as faults, jams, etc. can present significant problems in maintaining the integrity of a run in process. Automatic job recovery procedures generally assume a commonality of all sets in a job and compensate for malfunctions by simply completing any partial sets to make up for lost or damaged copies in the set without requiring rejection of sets or partial sets. Because copy sensitive sets are non-interchangeable, such recovery procedures are not adequate when copy sensitive jobs are processed by the system. These jobs must be handled in a special manner. Special handling of the jobs should further be performed both during normal operation of the system and upon recovery from any interruption in system operation.
The related art has disclosed printing systems which include job recovery operations.
U.S. Pat. No. 4,327,993 to Gauronski et.al. discloses a method and apparatus for performing job recovery in a reproduction machine wherein lost or damaged sheets in a set are remade with little operator intervention. A sensor which counts the number of sheets within a set is shown. A number of different job recovery methods for different problems are shown. A method of recovering from a recirculating document handler jam and a finisher jam are shown. Job recovery includes repriming or adding to copy sheets already in a dedicated tray to make up for lost or damaged copies in the set without having to reject a whole set having partial copies in process or copies destroyed in the operator intervention activity.
U.S. Pat. No. 4,190,354 to Smith et.al. discloses a copier job recovery system wherein a false bottom buffer tray is used to increase job recovery speed for duplex copies. Lost copy sheets are automatically replaced in proper serial order in the partial copy set by lifting the partial buffer copy set stack up with the false tray bottom and inserting replacement copies under the buffer set.
While the related art recognizes that job recovery can be performed automatically, the art does not differentiate between handling non-copy sensitive jobs and unique copy sensitive jobs.